Spring biasing means for a self-illuminating pushbutton

ABSTRACT

A self-illuminating pushbutton having a light reflective surface carried by a supporting platform slidably moveable within a casing toward and away from a character plate mounted adjacent an aperture at one end of the casing. An elongated resilient element integrally molded at each of two diagonally opposed corners of the supporting platform engages the inner walls of the casing so as to bias the supporting platform and light reflective surface away from the character plate, thereby making the character normally appear non-luminous.

[151 3,691,985 [451 Sept. 19, 1972 United States Patent Otterlei SPRING BIASING'MEANS FOR A SELF- 3,309,487 3/1967 Fisher........................200/172 3,403,236 9/1968 Zoludow......................200/67 ILLUMINATING PUSHBUTTON Primary Examiner-Louis J. Capozi Attorney-Merchant & Gould 4704 Merilane,

[72] Inventor:

[22] Filed:

' ABSTRACT A self-illuminating pushbutton having a light reflective .surface carried by a' supporting platform slidably [52] US. Cl. ..........;.'......116/124, 200/167, 200/172,

250/75 moveable within a casing toward, and away from a 9/00 116/114, 124; ZOO/67.5, 172, 200/167, 172 A, 159 A; 250/75, 79

[511 int.

character plate mounted adjacent an aperture at one [58] Field of Search end of the casing. An elongated resilient element integrally molded at each of two diagonally opposed comers of the supporting platform engages the inner walls of the casing so as to bias the supporting platform and light reflective surface away from the [56] References Cited UNITED STATES PATENTS character plate, thereby making the character normally appear non-luminous.

5 Claims, 5 Drawing Figures SPRING BIASING MEANS FOR A SELF- ILLUMINATING PUSHBUTTON BACKGROUND OF THE INVENTION The present invention pertains to a self-illuminating pushbutton.

Self-illuminating pushbuttons have found wide commercial usage. For example, they are frequently used in conjunction with pushbutton switches for providing a visual numerical indication when the switch is in a depressed or actuated position. Such pushbuttons are generally constructed from a casing having a character plate positioned adjacent an aperture in one end thereof. A light emitting surface is inserted into the easing to cause the character to appearluminous when depressed within the casing so as to be adjacent the character plate. On release of the depressing force, the light emitting surface is urged away fromthe character plate by a coil spring or springs thereby causing the character to appear non-luminous.

It is commercially desirable that self-illuminating pushbuttons are highly dependable, but yet, readily I Summary of the Invention The present invention provides a self-illuminating pushbutton having spring biasing means formed integrally with either the pushbutton casing or a moveable element for supporting a light emitting surface within the pushbutton casing. In either embodiment, the biasing means urge-the supporting element and light emitting surface in a direction away from a character plate mounted at an aperture in one end of the casing. In a preferred embodiment, the biasing means are in the form of an elongatedresilient element integrally molded at each of two diagonally opposed corners of a rectangular-shaped supporting platform. Each of these resilient elements extend generally arcuately within the casing in a direction longitudinally away from the character plate and transversely outward to abuttment an abutment on the inner walls of the casing.

By providing spring biasing means integrally formed (e.g. molded) with thepushbutton casing or supporting element, the present invention eliminates the utilization of the conventional coil spring(s) and accessory parts for biasing the light emitting surface and, consequently, the difficult task of installing the spring(s) and accessory parts within the pushbutton casing. In accordance with the preferred embodiment of the present invention, the spring biasing means is assembled concurrently with the insertion of the supporting element and light emitting surface into the pushbutton casing. This significantly facilitates the mass producibility of self-illuminating pushbuttons at a very low cost (relative to prior art pu'shbuttons utilizing a coil spring). Yet, the present invention provides a highly dependable self-illuminating pushbutton.

BRIEF DESCRIPTION OF THE DRAWINGS button as shown in FIG. 1;

FIG. 4 is a cross-sectional view along the lines 4-4 of FIG. 1; and

FIG. 5 is a cross-sectional viewalong the lines 5-5 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the numeral 10 generally designates the self-illuminating pushbutton provided by the present invention. As well as having numerous additional uses, pushbutton 10 can be used in conjunction with a pushbutton switch (now shown) so as to provide, for example, a visual numerical indication (e.g. the numeral 4) when the switch is in its actuated position. Such uses are well known in the art and will not be further described herein.

Pu'shbutton 10 includes means defining an outer shell or casing 12 having a first or forward portion 12a and an enlarged second or rearward'portion 12b. Casing portions l2a'and 12b each have a generally rectangular axial cross-section, but other shapes or designs can be utilized. As can be seen in the drawings, casing portion 12a includes an aperture 14 in a forward end 15 thereof and casing portion 12b includes two oppositely disposed lips 16:: and 16b projecting inwardly along the top and bottom inner sidewalls of portion 12b at a rearward end 17 thereof.

A character plate in the form of a translucent plastic plate 18 having an opaque, silk screened paint coating 19 on the inner surface thereof is inserted within casing portion 12a abutting aperture 14. Paint coating 19 defines a translucent character (e.g. the numeral 4). Plastic plate. 18 is fixedly held in position by an inner casingmeans 20 positioned withinouter casing 12. In this embodiment, inner casing 20 has a closed outer or rearward end portion 21. As can be seen particularly well in FIGS. 4 and 5, inner casing 20 fits snugly within forward casing portion 12a and includes a pair of flanges 22 projecting laterally outward from opposite vertical edges of closed end portion 21. As illustrated, the flanges 22 form small notches 23 along the rearward, top and bottom edges of the closed end portion 21. When assembled, flanges 22 abut the inner vertical sidewalls of casing portion 12b and the notches 23 coact with the lips 16a and 16b in a snap-lock manner to allow assembly and disassembly of pushbutton 10.

' Two diagonally'opposed openings 26a and 26b extend longitudinally through the closed end portion 21 between a cavity 27 adjacent character coating 19 and the rearward end of inner casing 20. Additionally, two diagonally opposed recesses 28a and 7, 28b extend generally longitudinally within closed end portion 21 from cavity 27 toward the rearward end of portion 21. Two openings 30a and 30b in the sidewalls of inner casing 20 communicate with recesses 28a and 28b, respectively.

. element or platform 36 having a resilient cushion 40 attached thereto. A light emitting surface 42, preferably in the form of a highly light reflective material, is attached .to the forwardsurface of cushion 40 facing character I coating 19. Other light emitting surfaces formed from, for example, a luminescent or fluorescent material can also be utilized. Resilient cushion 40 is not critical to the present invention and is only necessary when light reflective surface 42 must be moved slightly further forward after contacting character coating 19 so as, for example, to allow deactuation of certain types of pushbutton switches with which pushbutton may operate in conjunction. Further, light reflective surface 42 can be applied directly (e.g. by using a light reflective paint) to resilient cushion 40 or to platform 36 when the utilization of cushion 40 is unnecessary. Two rods 45 are attached to the rearward side of supporting platform 36 and extend through openings 26a and 26b protruding longitudinally outward from the rearward end 21 of inner casing 20.

The supporting platform 36 has an axialcross-section generally similar to the axial cross-section of cavity 27 and includes biasing means integrally formed thei'ewith for urging platfonn 36, resilient cushion 40 and reflective surface 42 away from character coating 19. As shown, the biasing means is in the form of two elongated resilient elements 50 integrally molded with platform 36 at diagonally opposed comers thereof. Elongated elements 50 extendtransversely along opposite edges of platform 36 in a slightly spaced relationship thereto and project laterally outward in opposite directions from platform 36. As can be seen in FIG. 3, elongated elements 50 are generally coplanar with platform 36 prior to the insertion of plunger element 35 into cavity 27. Preferably, the supporting platform 36 is formed from a highly resilient plastic material such as an acetal resin (e.g. Delrin, a product of 'E. I. DuPont de Nemours & Company) so as to provide a high degree of resiliency to elements 50.

. When pushbutton 10 is assembled, the resilient elements 50 are compressed rearwardly and inwardly as shown by the arrows in FIG. 3 so as to extend in a generally arcuate-manner (i.e..in a curved rearward direction) within cavity 27, recesses 28a .and 28b, and through the openings 30a and 30b, respectively, to engage a forward edge of the respective openings 30a and 30b as can be seen particularly well in FIG. 5. The inner walls of casing portion 12b have grooves 52 therein to prevent lateral movement of the free endsof compressed elements 50. This inward compression of resilient elements 50 urges the plunger element 35 away from character coating 19 until it engages the closed end 21 inner casing 20. This position of plunger element 35 (i.e. the deactuated or released position of pushbutton 10) is shown in FIGS. 4 and 5. Upon application of a forwardly directed force to rods 45, plunger element 35 moves forward within cavity 27 until the light reflective surface 42 contacts the character coating 19 causing the character defined thereby to appear luminous. In this depressed or actuated position, the engagement of resilient elements 50 with the forward edges of respective openings 30a and 30b causes the elements 50 to be further compressed than when pushbutton 10 is in its deactuated position. Consequently,

h as to provide the rearward biasing upon release of the forward pressure .applied to rods 45, the resilient spring elements 50 expand outwardly urging supporting platform 35 and light reflective surface 42 away from the character coating 19 and the character again appears non-luminous.

As will be apparent to one skilled in the art, the resilient elements50 can coact with the inner walls of casing 12 in numerous different ways and still provide the desired spring biasing function. For example, the resilient elements 50 can simply coact with a ridge or other suitable transverse abutment on the inner wall of section 12b or other elements without necessitating an inner casing 20. Also, resilient elements 50 can be formed integrally with the pushbutton casing in such a manner that the free ends of elements 50 coact with the supporting platform 35 or light emitting surface 42 so thereof.

' What is claimed is: I

l. A self-illuminating pushbutton, comprising:

a. a casing having an aperture at one end thereof;

b. a character plate mounted at said aperture;

c. a supporting element slidably moveable within said casing toward and away from said character plate and having a light emitting surface facing said character plate; and

d. spring biasing means integrally molded with said supporting element and projecting outward therefrom to engage said casing so as to urge said supporting element and light emitting surface away from said character plate.

2. A self-illuminating pushbutton, comprising:

a. a casing having an aperture at one end thereof;

b. a character plate mounted at said aperture;

c. a supporting element slidably moveable within said casing toward and away from said character plate and having a light emitting surface facing said character plate; and v d. spring biasing means including an elongated resilient member integrally molded at each of two oppositely disposed portions of said supporting element and projecting outward therefrom to engage said casing so as to urge said supporting element and light emitting surface away from said character plate.

3. The self-illuminating pushbutton of claim 2.

wherein:

a. said supporting element is moveable between forward and rearward positions within said casing; said light emitting surface causes said character to appear luminous in the forward position of said supporting element and non-luminous in the rearward position thereof;

c. said elongated resilient members each extend generally arcuately rearward within said casing expanding outwardly as said supporting element moves from the forward position to the rearward position thereof; and

. said casing defines a space in which said resilient members can undergo the outward expansion thereof.

4. The self-illuminatingpushbutton of claim 2 including means defining'an inner casing positioned within said casing having said aperture therein, wherein:

a. said inner casing includes a closed outer end portion, cavity adjacent said character plate and opsaid supporting element and light emitting surface is moveable within said cavity of said inner casing; and

. each of said resilient elements extend arcuately into a different one of said recesses and outward through said openings in the sidewalls of said inner casing to engage an edge of said openings.

A self-illuminating pushbutton, comprising:

casing means having an aperture at one end;

a character plate mounted adjacent said aperture;

mean defining a supporting element moveable within said casing toward and away from said character plate and having a light emitting surface facing said character plate; and

. spring biasing means molded integrally with one of said casing means and said supporting element means and engaging the other one of said casing means and said supporting element means for urging said supporting element and said light emitting surface away from said character plate.

l I t i 

1. A self-illuminating pushbutton, comprising: a. a casing having an aperture at one end thereof; b. a character plate mounted at said aperture; c. a supporting element slidably moveable within said casing toward and away from said character plate and having a light emitting surface facing said character plate; and d. spring biasing means integrally molded with said supporting element and projecting outward therefrom to engage said casing so as to urge said supporting element and light emitting surface away from said character plate.
 2. A self-illuminating pushbutton, comprising: a. a casing having an aperture at one end thereof; b. a character plate mounted at said aperture; c. a supporting element slidably moveable within said casing toward and away from said character plate and having a light emitting surface facing said character plate; and d. spring biasing means including an elongated resilient member integrally molded at each of two oppositely disposed portions of said supporting element and projecting outward therefrom to engage said casing so as to urge said supporting element and light emitting surface away from said character plate.
 3. The self-illuminating pushbutton of claim 2 wherein: a. said supporting element is moveable between forward and rearward positions within said casing; b. said light emitting surface causes said character to appear luminous in the forward position of said supporting element and non-luminous in the rearward position thereof; c. said elongated resilient members each extend generally arcuately rearward within said casing expanding outwardly as said supporting element moves from the forward position to the rearward position thereof; and d. said casing defines a space in which said resilient members can undergo the outward expansion thereof.
 4. The self-illuminating pushbutton of claim 2 including means defining an inner casing positioned within said casing having said aperture therein, wherein: a. said inner casing includes a closed outer end portion, cavity adjacent said character plate and oppositely disposed from said closed end portion, first and second recesses adjacent oppositely disposed sidewalls of said inner casing extending longitudinally from said cavity toward an end of said inner casing opposite said cavity and first and second openings in the sidewalls of said inner casing communicating with said first and second recesses, respectively; b. said supporting element and light emitting surface is moveable within said cavity of said inner casing; and c. each of said resilient elements extend arcuately into a different one of said recesses and outward through said openings in the sidewalls of said inner casing to engage an edge of said openings.
 5. A self-illuminating pushbutton, comprising: a. casing means having an aperture at one end; b. a character plate mounted adjacent said aperture; c. mean defining a supporting element moveable within said casing toward and away from said character plate and having a light emitting surface facing said character plate; and d. spring biasing means molded integrally with one of said casing means and said supporting element means and engaging the other one of said casing means and said supporting element means for urging said supporting element and said light emitting surface away from said character plate. 